(a) Field of the Invention
The present invention relates to an optical mask and a manufacturing method of a thin film transistor array panel using an optical mask.
(b) Description of Related Art
An active type display device such as a liquid crystal display (LCD) and an organic light emitting display (OLED) includes a plurality of pixels arranged in a matrix, field generating electrodes, and switching elements. The switching elements include thin film transistors (TFTs) having three terminals, i.e. a gate, a source, and a drain. The TFT of each pixel selectively transmits data signals to the field-generating electrode in response to gate signals.
The display device further includes a plurality of signal lines for transmitting signals to the switching elements, which include gate lines transmitting gate signals and data lines transmitting data signals.
The LCD and the OLED include a panel provided with the TFTs, the field-generating electrodes, and the signal lines, which is referred to as a TFT array panel.
The TFT array panel has a layered structure that includes several conductive layers and insulating layers. The gate lines, the data lines, and the field-generating electrodes are formed of different conductive layers and are separated by insulating layers.
The TFT array panel having the layered structure is manufactured by several lithography steps, following etching steps. Since the lithography requires cost and time, it is desirable to reduce the number of lithography steps.